The invention relates to a flowmeter for liquids, especially milk, when delivering the same from a tanker vehicle to stationary tanks, a centrifugal pump, an air eliminator and a volume meter being mounted in sequence starting at the tanker truck.
Precise metering of amounts is not feasible with known equipment of this kind because the centrifugal pump moves no air on the pressure side and hence one cannot set the required level for precise quantities at the end of the delivery process in the air eliminator. On the other hand, such equipment advantageously operates with centrifugal pumps because the latter allow large outputs.
The requirement of large output fails to be met therefore by another known kind of equipment, wherein a positive displacement pump, an air eliminator and a volume meter are mounted sequentially, starting with the tank truck. While the positive displacement pump allows sufficiently precise measurement of quantity, it is on the other hand limited as regards output, and may convey no more than 20,000 liters an hour for instance, because beyond a given size of the components of this pump, the required pressure build-up at the end of measurement may no longer be provided for air feed. This known equipment therefore may not be used economically when large deliveries of liquid must be undertaken, and besides, positive displacement pumps are fairly costly.